1661342243 has 8 divisors (see below), whose sum is σ = 1813304880. Its totient is φ = 1509534880.

The previous prime is 1661342239. The next prime is 1661342261. The reversal of 1661342243 is 3422431661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1661342243 - 2² = 1661342239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1661342213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15848 + ... + 59781.

It is an arithmetic number, because the mean of its divisors is an integer number (226663110).

Almost surely, 2^1661342243 is an apocalyptic number.

1661342243 is a deficient number, since it is larger than the sum of its proper divisors (151962637).

1661342243 is a wasteful number, since it uses less digits than its factorization.

1661342243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77637.

The product of its digits is 20736, while the sum is 32.

The square root of 1661342243 is about 40759.5662759063. The cubic root of 1661342243 is about 1184.3671941647.

The spelling of 1661342243 in words is "one billion, six hundred sixty-one million, three hundred forty-two thousand, two hundred forty-three".